The present invention generally relates to agricultural equipment, and devices which are utilized with agricultural equipment for controlling dust and other particulates generated from operation of the equipment. In particular, a mobile harvester is disclosed which is used for harvesting crops, such as nuts and/or fruits, where the harvester utilizes high volume air generated by an on-board fan to separate crops from foreign matter. The disclosed harvester addresses problems presented by the deposition of particulate matter into the air through the air exhaust of the harvester. The disclosed harvester comprises means for reducing dust and other particulate matter generated by the operation of the machinery which, by the nature of its operation, would otherwise generate substantial quantities of dust and disperse it into the atmosphere. The general mechanisms employed by the disclosed harvester capture and immobilize dust particles before the particles are dispersed into the atmosphere by the fan exhaust emitted from the machinery.
Dust generation by agricultural and construction machinery is a known problem, particularly in arid areas. To name just a few problems caused by the dust generation, dust particles result in air pollution, water pollution, soil loss, human and animal health problems, and potentially hazardous reductions in visibility. In addition, the dust can adversely impact the health of various plants. In an effort to reduce dust production, some air pollution control districts impose various operating limitations on farm machinery or otherwise impose different dust control measures.
Dust generation from nut and fruit harvesting equipment can be particularly problematic. These devices typically utilize high volume fans to separate nuts and/or fruit from the debris which may be picked up by the harvesting equipment, including leaves, branches, dirt clods, soil, etc. (collectively, “foreign material”). However, a large portion of the foreign material is typically blown out through the fan discharge, resulting in the dispersion of a large volume of dust into the atmosphere. An example of such a harvester is disclosed in U.S. Pat. No. 4,364,222, which is incorporated herein by this reference. In these devices, a mixture of fruit or nuts (generally referred to as “crops”) and foreign material is picked up and deposited on conveyors enclosed by a housing connected to a fan inducing a vigorous flow of air through the conveyors. Various baffles, walls and guide plates direct the air so as to enhance the separation of the desirable crops from the foreign material. However, a substantial volume of foreign material is typically discharged into the atmosphere with a minimum amount of processing, thus creating a large discharge of dust.